Brake-valve device



o? May 3,1927. L' A FOWLER( BRAKE VALVE DEVI CE Filed Aug. 6, 1925 S I xN'vENToR ATTORNE Patented May 3, 1927.

A UNITED STATES PATENT OFFICE.- y

LESTER A. FOWLER, F BERKELEY, CALIFORNIA, ASSIGNOR TO THE WESTINGHOUBE AIR BRAKE COMPANY, OF WILMERDDTG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

BRAKE-VALVE DEVICE.

Application led August 6, 1925. Serial No. 48,441.

This invention relates to fluid pressure brakes and to a brake valve device adapted more particularly to be used in connectlon with automotive fluid pressure brakes.

The principal object of my invention is-to provide an improved brake valve device of the above character. 'A

In the accompanying drawing, the single figure is a View, partly in section, showing a brake lvalve device embodying my lnvention, and shown associated with a brake chamber and a reservoir.

As shown in the drawing, the brake valvedevice may comprise a casing .l having a piston chamber 2 containing a piston 3 having guide wings 5 and sub]ect on one side to the pressure of a coil spring 4 and having the chamber at the oppositeside open to an atmospheric exhaust port 18. The plston chamber 2 at the spring' side of piston 3 1s connected through a pipe (3 with a brake chamber 7, an increase in Huid pressure 1n 'which is adapted to etiect an application of the brakes.

A supply valve 8 contained in valve chamber 9 isdisposed in axial alinement with piston 3 and is subject on one side to the pressure ofa' coil spring 10, sa1d valve being adapted to control communicatlon from a reservoir 11 to piston chamber 2 and the brake chamber 7 Integrally connected with the supply valve 8 is a ball shaped exhaust valve 12. adapted to control the eX haust'ot' fluid from the brake chamber 7v by engaging a seat surrounding an exhaust port 13 which extends through the piston 3, said valve being made ball-shaped in order to compensate for any inaccuracies in alnement between the valve and the piston and thus ensure a tight seat.

Engaging the piston 3 is a coil spring 14, and applied to the outer end ot' the spring is a spring stem 15 which extends out through the casing 1. Pivotally mounted on a lug 1'9 is a lever 1G, one end of which is provided with a concave recess 17 adapted to receive the projecting convex end of spring stem 15, while the opposite end of said lever arm is suitably connected to a hand or foot operated device (not shown), which is within easy reach of the operator.

When it is desired to effect an application of the brakes, the lever arm 16 is operated to. compress the spring 14, which acts to shift the piston 3 so as to'cause the ball shaped exhaust valve 12 to first seat against the valve seat surrounding passage 13, and then upon a further movement the supply valve 8 1s unseated. Fluid under pressure from the reservoir 11 then flows past unseatcd valve 8 and through pipe 6 to brake chamber 7 When the pressure of fluid in the brake chamber and on the piston 3 has luci-eased to a degree slightlyy greater than the pressure exerted by spring 14 on the opposite side of said piston, the piston will be shifted so as to permit the supply valve 8 to be seated by spring 10 and still mainta1n the ball-shaped exhaust valve seated, closlng 'exhaust passage 13.

When it is desired to release the brakes, the lever arm 16 is operated so that the pressure on spring 14 is relieved, which permits the pressure of fluid in thebrake chamber and the pressure exerted byspring 4 to shift the piston 3, so that the exhaust valve -12 will be unseated. Fluid from the brake chamber then flows through pipe 6, passage 13, and to atmosphere through atmospheric exhaust port 18.

It will be evident that Vthe brakes may be gradually applied or released as desired by gradually increasing or diminishing the force applied to the spring 14 by the movement ot' lever arm 16.

- Any tendency of the spring stem 15 to cock, when pressure is applied to the lever arm 16, is prevented by the ability of the rounded end'of the stem to readily slide on the concave surface of the recess 17.

Having now-described my invention, what I claim as new and desire to secure by Let- 1. In a fluid pressure brake, the combina-` tion with a brake chamber, of a brake valve device comprising a casing, a piston in said casing having the chamber at one side cons nected to the brake chamber and the chamber at the opposite side connected to the atmosphere and having anexhaust passage, a 'supply valve for controlling the Vsupply of Huid under pressure to said brake chamber,

and a ball-shaped exhaust valve associated with said supp y valve and controlling oommunication through said exhaust passage.

2. In a fluid pressure brake, the combination with a brake chamber, of a brake valve device com rising a casing, a ball-shaped exhaust va ve for controlling communlcation through said exhaust passage and op-A erable by said piston arid a su l valve movable with said elhaust valvgpfr 5 trolli to sai brake chamber.

my hand..

LESTER A. FOWLER.

oon-"l0 the supply of fluid under pressure i 'In tesiimony whereof I have hereunto setl 

